Background

The pathophysiology of microscopic colitis (MC) is not fully understood. A dysregulation of the adaptive immune response of which the maturation and function is imprinted in early life, has been hypothesized. Lack of early childhood exposure to infectious agents and symbiotic microorganisms may increase the risk of MC in later life. Various other factors (e.g. female hormone exposure, educational level) have been associated with MC, but often with minimal or conflicting evidence. Therefore, we aimed to evaluate whether exposure to (microbial) agents in early life might be protective for MC development and to assess the role of several less well-established risk factors for MC in one study.

Methods

A case-control study was performed including MC cases diagnosed in the southern part of the Netherlands between 2000–2012. Cases were identified in the national pathology registry and biopsy slides were revised to confirm the diagnosis. All included cases were matched to non-MC controls from the same geographical area, based on gender and year of birth. All subjects filled out a questionnaire on various risk factors, including e.g. proxy measures for early life microbial exposure, female hormone exposure, passive smoking and self-reported comorbidities. For the cases, the index date was defined as the date of diagnosis, controls were assigned the same index date as their matched case.

Conclusion

Early life exposure to microbial antigens was not protective for MC in later life. Furthermore, female hormone exposure, educational level and passive nicotine exposure were not associated with MC. We did confirm the association between smoking and MC. Exposure to environmental risk factors in later life may be of relevance in MC pathogenesis and warrants further investigation.